1. Technical Field
The present invention relates to an apparatus for helping to protect a vehicle occupant in the event of a vehicle collision. In particular, the present invention relates to restraining movement of a portion of a vehicle seat with a length of seat belt webbing in the event of a vehicle collision.
2. Description of the Prior Art
A known apparatus, as disclosed in U.S. Pat. No. 5,401,072 to Farrand, includes first and second lengths of belt webbing. The first length extends about the occupant and has opposite ends anchored to the vehicle. In the event of a vehicle collision, the occupant tends to move relative to the vehicle and is restrained by the first length of belt webbing.
The second length of belt webbing extends behind a seat back portion of the vehicle seat and has opposite ends anchored to the vehicle. In the event of a vehicle collision, the seat back portion may tend to move rearward relative to the vehicle and is restrained from rearward movement by the second length of seat belt webbing.
The present invention is an apparatus for helping to protect an occupant of a vehicle upon the occurrence of a vehicle collision. The apparatus includes a vehicle seat, a length of seat belt webbing, a seat belt retractor, and a blocking mechanism. The vehicle seat has a seat back portion for engaging the body of the occupant of the vehicle. The length of seat belt webbing extends around a portion of the occupant and helps to protect the occupant upon the occurrence of a vehicle collision. The seat belt retractor biases the length of seat belt webbing in a belt retraction direction. The seat belt retractor allows the length of seat belt webbing to move in a belt withdrawal direction when a predetermined force is applied to the length of seat belt webbing. The belt withdrawal direction is opposite the belt retraction direction. The blocking mechanism blocks movement of the length of seat belt webbing in the belt withdrawal direction. The blocking mechanism is actuated upon the occurrence of a vehicle collision. A portion of the length of seat belt webbing restrains movement of the seat back portion relative to the vehicle during a vehicle collision.